The maintenance and upkeep of recreational aquatic facilities, such as pools, saunas, fountains, spas, and hot tubs, can be burdensome, time-consuming, and costly. This is in large part due to the rigorous demands of manual monitoring and regulating the hardness in the water found in an aquatic facility (hereinafter “recreational water”), the pH of the recreational water, and the need to regulate the chemistry to prevent bacterial and fungal growth. Further, this upkeep is environmentally burdensome on the water supply, especially in the dryer hotter portions of the country, due to the need to replace the recreational water when the water hardness becomes too high. This water hardness is caused by the high evaporation rates, which concentrates the minerals in the aquatic facility and thus requires replacement periodically because of excessive hardening of the water, typically every one to five years. The water evaporation rates for outdoor aquatic facilities can reach over 100 inches per year in the Southwest. This hardened water is also an environmental detriment in that the drained recreational water is not useful for other purposes without treatments to remove chemicals and other substances commonly found in recreational water.
Recreational water hardness generally is proportional to the content of certain minerals and chemicals in the water, particularly cations such as calcium and magnesium. Generally, the more cations dissolved in the water, the harder the water is, and water hardness is generally measured as an equivalent amount of calcium carbonate (CaCO3) or sometimes calcium content alone.
Thus, if the calcium content of the recreational water is too low, the recreational water hardness is also low. If the calcium content remains low, this can result in the detrimental effect of leeching of minerals out of the walls of the aquatic facility, which in turn can cause wall deterioration, and eventually lead to unsightly changes in the aquatic facilities surfaces and the possibility of water leaks in the aquatic facility. If, on the other hand, the calcium content of an aquatic facility is too high, then generally the recreational water hardness is also high. If the calcium content remains high, the detrimental effect of calcium deposits forming and scaling can occur, thereby forming unsightly stains, including white lines, on the surfaces and walls of the aquatic facility. Such staining can further lead to expensive cleaning or repair bills of the aquatic facility. Also, the harder the water, i.e. high calcium content, increasing amounts of chemicals are needed to maintain the status quo of the recreational water chemistry, such as pH. This occurs because many of the added chemicals react with the high calcium content in the water to form salts.
Furthermore, if the calcium content of the aquatic facility increases, so does the amount of total dissolved solids (TDS) in the water. Generally, a high calcium hardness level can cause a high level of TDS in the water. Calcium hardness is only one part of TDS. TDS refers to all minerals, chemicals, cations, anions, inorganic salts, and organic matter dissolved in water (hereinafter collectively referred to as “dissolved solids”). Thus, TDS includes water hardness, alkalines, chlorides, bromides, silicates, sulfates, cyanuric acid, and organic compounds. Each time something is added to recreational water, such as a sanitizer, a pH adjusting chemical, a conditioner, a tile/surface cleaner, an algaecide, and the like, the amount of TDS in the recreational water can increase. This can lead to a buildup of TDS.
Typically, particularly when temperature is high and humidity is low, the recreational water in the aquatic facility can quickly evaporate, leaving behind undesirable dissolved solids in the aquatic facility. Because the water can evaporate but the TDS do not evaporate over time there is a buildup of TDS. When the level of TDS in an aquatic facility is too high to cost effectively regulate the water chemistry, the recreational water must be completely or partially drained and the aquatic facility refilled with a fresh supply of water. In areas, such as the Southwest, where water is a scarce environmental resource, the requirement to drain and refill the water of the aquatic facility can be expensive, wasteful, and have a detrimental environmental impact. What is needed is a cost-effective system, method and apparatus to control the recreational water calcium hardness and total dissolved solids and thus eliminate or extend the interval between recreational water replacement.